Lager Fermentation Temp was Too High!!

[EvolutionAles]

I brewed a Doppelbock with a SG of 1.090 and fermented at 50F for two weeks using White Labs WLP833. The power went out to the chest freezer some point after the last time it was checked (about two weeks after start of fermentation) and the temps rose to 65F for about 5 days before I found out. The gravity right now is 1.030 and the yeast are highly active. I'm dropping the temperature back down to 55F, should I put it back to 50F like it was or will that drop out all the yeast? What gravity should it be at before the diacetyl rest?

 

[GoeHaarden]

Just want to clarify that it did make it two weeks at 50F? It sounds like you passively performed a diacetyl rest, and I'd honestly probably let it sit at ~65F until it finishes. I typically go to 68F for my d-rests and let it finish at that temp before I lager.

As far as when to do a diacetyl rest, who knows honestly. Some say 75% of expected attenuation, others say 80%, and some don't do one at all. I don't like opening my fermenters if I don't have to so I typically do my d-rest at 8-10 days. Never had an issue, and never had any perceivable diacetyl...

 

[TooManyTacos]

I definitely wouldn't worry about it. Many people are warm fermenting lagers with great results. I still have a cold fermented lager that was fermented at 52 degrees F and has aged beautifully. I'm planning on making a lager fermented at 66 degrees F for my next batch to compare side by side to see how different it tastes.